<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>
	<body>
		<script type="text/javascript">
	      
			var num1=parseFloat(prompt("请输入第一个数："));
			var num2=parseFloat(prompt("请输入第二个数：",""));
			var yunsuan=prompt("请输入运算符号：","");
			var jieguo;
			switch (yunsuan){
				case "+":
				jieguo=num1+num2;
				break;
				case "-":
				jieguo=num1-num2;
				break;
				case "*":
				jieguo=num1*num2;
				break;
				case "/":
				jieguo=num1/num2;
				break;
			}
			alert("两数运算结果为："+num1+yunsuan+num2+"="+jieguo)
		</script>
	</body>
</html>
